CN118022701A - Small-pore silica gel clarifying agent and preparation method and application thereof - Google Patents

Small-pore silica gel clarifying agent and preparation method and application thereof Download PDF

Info

Publication number
CN118022701A
CN118022701A CN202410430786.4A CN202410430786A CN118022701A CN 118022701 A CN118022701 A CN 118022701A CN 202410430786 A CN202410430786 A CN 202410430786A CN 118022701 A CN118022701 A CN 118022701A
Authority
CN
China
Prior art keywords
silica gel
acid
clarifier
small
preparing
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
CN202410430786.4A
Other languages
Chinese (zh)
Other versions
CN118022701B (en
Inventor
房昊
孙博雅
崔玉玲
张红梅
刘海霞
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Qilu University of Technology
Original Assignee
Qilu University of Technology
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Qilu University of Technology filed Critical Qilu University of Technology
Priority to CN202410430786.4A priority Critical patent/CN118022701B/en
Publication of CN118022701A publication Critical patent/CN118022701A/en
Application granted granted Critical
Publication of CN118022701B publication Critical patent/CN118022701B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Classifications

    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01JCHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J20/00Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
    • B01J20/28Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof characterised by their form or physical properties
    • B01J20/28054Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof characterised by their form or physical properties characterised by their surface properties or porosity
    • B01J20/28057Surface area, e.g. B.E.T specific surface area
    • B01J20/28064Surface area, e.g. B.E.T specific surface area being in the range 500-1000 m2/g
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01JCHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J20/00Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
    • B01J20/02Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof comprising inorganic material
    • B01J20/10Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof comprising inorganic material comprising silica or silicate
    • B01J20/103Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof comprising inorganic material comprising silica or silicate comprising silica
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01JCHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J20/00Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
    • B01J20/22Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof comprising organic material
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01JCHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J20/00Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
    • B01J20/28Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof characterised by their form or physical properties
    • B01J20/28054Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof characterised by their form or physical properties characterised by their surface properties or porosity
    • B01J20/28078Pore diameter
    • B01J20/28083Pore diameter being in the range 2-50 nm, i.e. mesopores
    • CCHEMISTRY; METALLURGY
    • C02TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02FTREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00Treatment of water, waste water, or sewage
    • C02F1/28Treatment of water, waste water, or sewage by sorption
    • C02F1/288Treatment of water, waste water, or sewage by sorption using composite sorbents, e.g. coated, impregnated, multi-layered
    • CCHEMISTRY; METALLURGY
    • C12BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
    • C12HPASTEURISATION, STERILISATION, PRESERVATION, PURIFICATION, CLARIFICATION OR AGEING OF ALCOHOLIC BEVERAGES; METHODS FOR ALTERING THE ALCOHOL CONTENT OF FERMENTED SOLUTIONS OR ALCOHOLIC BEVERAGES
    • C12H1/00Pasteurisation, sterilisation, preservation, purification, clarification, or ageing of alcoholic beverages
    • C12H1/02Pasteurisation, sterilisation, preservation, purification, clarification, or ageing of alcoholic beverages combined with removal of precipitate or added materials, e.g. adsorption material
    • C12H1/04Pasteurisation, sterilisation, preservation, purification, clarification, or ageing of alcoholic beverages combined with removal of precipitate or added materials, e.g. adsorption material with the aid of ion-exchange material or inert clarification material, e.g. adsorption material
    • CCHEMISTRY; METALLURGY
    • C02TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02FTREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F2103/00Nature of the water, waste water, sewage or sludge to be treated
    • C02F2103/34Nature of the water, waste water, sewage or sludge to be treated from industrial activities not provided for in groups C02F2103/12 - C02F2103/32
    • C02F2103/343Nature of the water, waste water, sewage or sludge to be treated from industrial activities not provided for in groups C02F2103/12 - C02F2103/32 from the pharmaceutical industry, e.g. containing antibiotics

Landscapes

  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Engineering & Computer Science (AREA)
  • Analytical Chemistry (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Bioinformatics & Cheminformatics (AREA)
  • Genetics & Genomics (AREA)
  • Health & Medical Sciences (AREA)
  • Biochemistry (AREA)
  • Water Supply & Treatment (AREA)
  • General Engineering & Computer Science (AREA)
  • General Health & Medical Sciences (AREA)
  • Food Science & Technology (AREA)
  • Wood Science & Technology (AREA)
  • Zoology (AREA)
  • Environmental & Geological Engineering (AREA)
  • Hydrology & Water Resources (AREA)
  • Inorganic Chemistry (AREA)
  • Nanotechnology (AREA)
  • Silicon Compounds (AREA)

Abstract

The invention belongs to the technical field of wastewater purification treatment, and particularly relates to a small-pore silica gel clarifier, and a preparation method and application thereof. The preparation method comprises (1) preparing sol: firstly, adding a hydroxyl reversible shielding agent into a raw material sodium silicate solution, and then adding a raw material sulfuric acid solution into the sodium silicate solution; (2) preparing a gel: aging, alkali soaking and water washing are carried out on the sol; (3) preparing a small-pore silica gel clarifier: drying and activating the gel. The preparation method can prepare the silica gel clarifier with small pore diameter and rich surface hydroxyl groups, realizes high-selectivity adsorption in the clarification and purification treatment processes of medical wastewater and the like, and achieves the purpose of specific adsorption. The prepared small-pore silica gel clarifier can be applied to the purification treatment of medical wastewater. In addition, the small-pore silica gel clarifier can be applied to the haze prevention treatment of beer, realizes high-selectivity adsorption of haze sensitive proteins, and improves the clarity of beer.

Description

Small-pore silica gel clarifying agent and preparation method and application thereof
Technical Field
The invention belongs to the technical field of wastewater purification treatment, and particularly relates to a small-pore silica gel clarifier, and a preparation method and application thereof.
Background
The adsorption clarification method is a technology for adding a clarifying agent into liquid to be clarified, removing substances which are easy to generate turbidity in an adsorption mode by utilizing the adsorption characteristic of the clarifying agent, retaining other effective substances, and realizing purification and improving the clarity of the liquid. The adsorption clarification method has a very wide application range, and can be applied to the purification treatment of medical wastewater. The medical wastewater is characterized by high content of organic matters such as antibiotics, strong biological activity, deep chromaticity and high salt content, and belongs to industrial wastewater which is difficult to treat.
Patent CN101565223a discloses a clarifying agent comprising sepiolite, alum, calcium carbonate, ascorbic acid. The clarifier interacts with proteins in the wastewater to produce sediment, which more effectively clears the wastewater. However, the turbidity removal clarifier disclosed in the patent has poor adsorption selectivity, and cannot achieve specific adsorption.
The adsorption clarifying agent commonly used at present comprises natural clarifying agent, chitosan clarifying agent, gelatin and the like. The natural clarifier is an extracted natural polymer substance, and the main component is natural polysaccharide. The chitosan is sugar or fiber separated from the outer layer of bones of crustaceans such as crabs, shrimps and the like, is the only alkaline polysaccharide in the natural polysaccharide, and forms a crystallization area through the interaction of a plurality of hydrogen bonds and amino groups on a molecular chain, so that the chitosan has the characteristics of good flocculation effect, no toxicity, no smell, biodegradability, bacterial activity inhibition and the like. The gelatin clarifier is water-soluble high molecular polymer and has good flocculation property, and the main characteristic is that suspended matters can be flocculated in the glue solution through electric neutralization and bridging adsorption, and the gelatin clarifier can form high molecular and high ionic degree in the high-concentration glue solution. However, these clarifying agents are expensive and have a large amount of use, and if they are used for the turbidity removal and purification treatment of sewage and the like, the treatment cost increases; secondly, the clarifying agents have poor tolerance to acid, alkali and salt, and cannot adapt to complex chemical environments such as medical wastewater.
The silica gel with the surface rich in hydroxyl is amorphous solid powder with a microporous structure, has the main component of mSiO 2·nH2 O, is insoluble in water and any solvent except caustic soda and hydrofluoric acid, does not react with any acid, alkali or salt, has the advantage of stable chemical property, is nontoxic, tasteless and incombustible, and has stronger stability. It is based on these excellent physicochemical properties of silica gel, which is used as a clarifying agent without a leachable substance; easy to filter and clean after use; is nontoxic and tasteless, and is the safest clarifier at present. In addition, silica gel has a significant cost advantage over other adsorbents such as crosslinked polyvinylpyrrolidone (PVPP) and is therefore considered a very desirable clarifying agent.
However, in the practical application of the conventional silica gel, such as adsorption and purification treatment of wastewater, for example, in the adsorption and purification treatment process of medical wastewater containing antibiotics, the adsorption selectivity is low, and the differential and specific adsorption cannot be realized. Therefore, development of a novel silica gel clarifier with strong adsorption selectivity is needed to achieve the purpose of specific adsorption.
Disclosure of Invention
The invention aims to solve the problem that the existing silica gel clarifier has poor adsorption selectivity in the adsorption clarification and purification treatment process of medical wastewater and the like, and provides a preparation method of the silica gel clarifier with small pore diameter.
It has been found that substances which are generally prone to haze have smaller particle sizes, whereas the active substances which need to be retained are generally of relatively larger particle sizes. The prior silica gel clarifier has larger pore diameter, not only can reduce the specific surface area, but also can diffuse some effective substances with relatively larger particle diameter which need to be reserved into pore channels with huge surface area, thereby leading each substance in the sewage to be indiscriminately adsorbed and reducing the adsorption selectivity of substances which are easy to generate turbidity. If the selective separation can be carried out by utilizing the particle size difference between the silica gel clarifying agent and the silica gel clarifying agent, the silica gel clarifying agent is hopeful to prevent the effective substances with relatively large particle sizes from diffusing into the pore channels through smaller pore sizes, so that the occurrence of unexpected adsorption is reduced; meanwhile, substances with smaller particle size and easy generation of turbidity are not influenced to diffuse into the pore canal, and adsorption occurs on the inner surface of the silica gel, so that the aim of selectively removing turbidity is fulfilled.
It can be seen how to realize accurate control of the pore size of the silica gel adsorption material is critical for solving the technical problems. In the traditional preparation process, the most critical step for forming the microstructure of the silica gel is to add dilute sulfuric acid into a sodium silicate solution for acidification, so that silicate ions and hydrogen ions are combined to generate orthosilicic acid, and the orthosilicic acid is unstable and can spontaneously dehydrate and condense to form polysilicic acid. The formation of polysilicic acid in this stage has a crucial influence on the pore structure and the number of surface hydroxyl groups of the final silica gel product. In general, the dehydration condensation degree of the orthosilicic acid is difficult to effectively control, the reaction rate is often only regulated by the temperature or the pH value of the solution, excessive condensation of the orthosilicic acid is easy to be initiated, and the pore canal is closed or less pore canals are unfavorable for the selective diffusion adsorption of the sewage turbidity removal treatment.
In order to solve the problem, the invention provides an acidification-aging invention conception of reversible shielding of silicon hydroxyl, and the invention can inhibit excessive polymerization of the orthosilicic acid by carrying out reversible shielding on the hydroxyl on the orthosilicic acid, so that the polymerization degree is highly controllable, the inhibition of dehydration condensation of the orthosilicic acid and the precise control of the condensation degree are realized, the pore diameter of the silica gel clarifying agent can be precisely regulated within a certain range, and the clarity of purified liquid is improved. Moreover, a certain amount of hydroxyl groups on the surface of the silica gel can be reserved at the same time, the hydroxyl number retention rate reaches 65% -90%, and the quantity loss caused by the excessive silicon hydroxyl groups participating in the excessive dehydration condensation reaction of the orthosilicic acid is avoided, so that the influence on the binding capacity of the silica gel on substances which are easy to generate turbidity is avoided, and the influence on the clarification effect is avoided.
The specific technical scheme is as follows:
The preparation method of the small-pore silica gel clarifying agent comprises the following steps:
(1) Preparing sol:
Firstly, adding a hydroxyl reversible shielding agent into a raw material sodium silicate solution, and uniformly mixing; then adding the raw material sulfuric acid solution into the sodium silicate solution, mixing and reacting at 20-40 ℃, and regulating the pH value of the mixed system to 2-4; after the reaction is finished, maintaining the pH value at 3-4 to prepare the sol.
The hydroxyl reversible shielding agent is compounded by an esterification reaction accelerator, a carboxyl activating agent and carboxylic acid; wherein, carboxylic acid: esterification reaction accelerator: the molar ratio of the carboxylic acid group activator is 0.1-5:1:0.5-2; the carboxylic acid: the molar ratio of the sodium silicate is 0.5-10:1.
The carboxylic acid is one or more of propionic acid, butyric acid, valeric acid, caproic acid, benzoic acid, phenylacetic acid, succinic acid, adipic acid, phthalic acid, isophthalic acid, terephthalic acid, fumaric acid or maleic acid.
The carboxyl activating agent is one or more of 1-ethyl- (3-dimethylaminopropyl) carbodiimide hydrochloride (EDCI), dicyclohexylcarbodiimide (DCC), diisopropylcarbodiimide (DIC) or 1- (3-dimethylaminopropyl) -3-Ethylcarbodiimide (EDC).
The esterification reaction accelerator is one or more of N-hydroxysuccinimide, N-hydroxysulfosuccinimide or N-hydroxysulfosuccinimide.
(2) Preparing gel: aging the sol obtained in the step (1) and soaking with alkali, and washing with water washing liquid to obtain gel; wherein the water washing liquid consists of ethanol and alkaline aqueous solution with pH value of 9-14.
The purpose of washing with the washing liquid is to carry out hydrolysis reaction on the ester formed by combining carboxylic acid and silicon hydroxyl under proper conditions, and then the silicon hydroxyl and free carboxylic acid on the surface of the silica gel are generated by re-hydrolysis reduction, and finally the recovery of a certain number of hydroxyl on the surface of the silica gel is realized, so that the silica gel pore structure is accurately regulated and controlled, a certain number of surface silicon hydroxyl can be maintained, and the quantity loss of excessive silicon hydroxyl caused by the excessive dehydration condensation reaction of the ortho-silicic acid is avoided, and the subsequent adsorption of substances which are easy to generate turbidity is influenced. Meanwhile, the hydrolyzed carboxylic acid and other impurities can be removed by water washing.
(3) Preparing a small-pore silica gel clarifying agent: and (3) drying and activating the gel prepared in the step (2) to obtain the small-pore silica gel clarifying agent.
According to the preparation method, firstly, the hydroxyl reversible shielding agent compounded by the esterification reaction accelerator, the carboxyl activating agent and the carboxylic acid is added into the raw material sodium silicate solution, so that the hydroxyl reversible shielding agent added in advance can play a role in the stage that the sodium silicate is acidified by sulfuric acid to generate the orthosilicic acid and the orthosilicic acid is initially polymerized to generate the oligomeric silicic acid, the excessively rapid increase of the concentration of hydroxyl on the orthosilicic acid in a reaction system can be restrained, the reaction potential and Gibbs free energy of the spontaneous dehydration polymerization of the orthosilicic acid hydroxyl to form the polysilicic acid are reduced, and the reaction rate of the dehydration polymerization process from the orthosilicic acid to the polysilicic acid is controllable.
The specific action mechanism is as follows: the three components in the hydroxyl reversible shielding agent cooperate with each other, and under the existence of the esterification reaction accelerator and the carboxyl activating agent, the carboxylic acid becomes a temporary shielding or protecting agent for silicon hydroxyl, namely, under the catalysis of the esterification reaction accelerator and the carboxyl activating agent, the carboxylic acid and the hydroxyl on the orthosilicic acid undergo esterification reaction to form silicate-carboxylic ester.
The dehydration condensation of orthosilicic acid is essentially that four hydroxyl groups contained in orthosilicic acid are dehydrated and condensed with each other, and the hydroxyl groups of two adjacent orthosilicic acids are condensed to remove one water molecule, thereby forming polysilicic acid (i.e., silica gel). Therefore, the rate and the degree of polymerization of the orthosilicic acid can be controlled as long as the hydroxyl number of the orthosilicic acid in the reaction system can be controlled, thereby realizing the precise control of the generation and the condensation of the orthosilicic acid. However, if the number of hydroxyl groups to be polymerized with each other is too small, the polymerization of the orthosilicic acid is insufficient, the obtained silica gel is not dense, and many pores, gaps and the like remain in the middle. Therefore, the addition amount and the reaction temperature of carboxylic acid, an esterification reaction accelerator and a carboxyl activating agent need to be accurately regulated, and the proportion of silicon hydroxyl groups in the reaction system to participate in the esterification reaction and the esterification reaction rate can be controlled, so that the surface hydroxyl groups of the orthosilicic acid are accurately and quantitatively shielded.
In the invention, the mass fraction of the sodium silicate solution in the step (1) of the preparation method of the small-pore silica gel clarifier can be 2-50 wt%, and the mass fraction of the sulfuric acid can be 2-70 wt%.
In the invention, carboxylic acid in the hydroxyl reversible shielding agent in the step (1) of the preparation method of the small-pore silica gel clarifying agent: esterification reaction accelerator: the molar ratio of the carboxylic acid group activator is 1:1:1.
In the invention, the carboxylic acid in the hydroxyl reversible shielding agent in the step (1) of the preparation method of the small-pore silica gel clarifying agent is one or more of butyric acid, caproic acid, benzoic acid, succinic acid, terephthalic acid or fumaric acid.
In the invention, the alkaline aqueous solution in the step (2) of the preparation method of the small-pore silica gel clarifier can be a K 2CO3 aqueous solution or a Na 2CO3 aqueous solution with the mass fraction of 2-90 wt%.
In the invention, ethanol in the water washing liquid in the step (2) of the preparation method of the small-pore silica gel clarifier is as follows: the volume ratio of the alkaline aqueous solution is 0.1-10:1.
In the invention, the water washing temperature in the step (2) of the preparation method of the small-pore silica gel clarifying agent is 10-80 ℃.
In the invention, the drying temperature in the step (3) of the preparation method of the small-pore silica gel clarifying agent is 60-180 ℃, and the drying time is 2-48h.
In the invention, the activation in the step (3) of the preparation method of the small-aperture silica gel clarifying agent adopts a roasting method, the roasting temperature is 400-500 ℃, and the roasting time is 2-96h.
The small-pore silica gel clarifying agent is prepared by the preparation method of the small-pore silica gel clarifying agent; the pore diameter of the silica gel clarifying agent is 4-8nm, the specific surface area is 550-800m 2/g, and the retention rate of silicon hydroxyl is 65-90%.
The application of the small-pore silica gel clarifying agent is that the small-pore silica gel clarifying agent is used for purifying medical wastewater or preventing turbidity of beer.
The small-pore silica gel clarifier is applied to the turbidity prevention treatment of beer, can effectively distinguish the turbid proteins to be removed from the foam proteins to be reserved in the beer liquid, realizes the high-selectivity adsorption of the turbid sensitive proteins, improves the clarity of the beer, and improves the quality of the beer. When used for the haze-preventing treatment of beer, the following steps can be adopted: firstly, adding the small-pore silica gel clarifier into beer to be treated at the temperature of 5-25 ℃ for stirring and reacting for 1-2.5h; wherein, the small pore silica gel clarifier: the mass ratio of the beer is 1:5-10; and then filtering out the small-pore silica gel clarifying agent.
The beneficial effects of the invention are as follows: based on the reversible shielding of the silicon hydroxyl on the orthosilicate, the invention provides the acidification-aging invention conception of the reversible shielding of the silicon hydroxyl for the first time, namely, the hydroxyl reversible shielding agent compounded by an esterification reaction accelerator, a carboxyl activating agent and carboxylic acid is added into a raw material sodium silicate solution. The proportion of silicon hydroxyl groups in the reaction system to participate in the esterification reaction and the esterification reaction rate can be further controlled by precisely controlling the addition amount and the reaction temperature of the carboxylic acid, the esterification reaction accelerator and the carboxyl activating agent, spontaneous dehydration condensation of the orthosilicate is inhibited, the surface hydroxyl groups of the orthosilicate are precisely and quantitatively shielded, further, the highly controllable polymerization of the orthosilicate and the controllable regulation of the silica gel pore channel structure are realized, and the pore diameter of the silica gel clarifying agent can be precisely regulated within a certain range.
Hydroxyl groups are the structural basis of the adsorptivity of silica gel, which is capable of adsorbing substances prone to turbidity, i.e. the bonding of a large number of hydroxyl groups on the surface. Therefore, in order to ensure the excellent adsorption capacity of the silica gel, a certain number of hydroxyl groups must be reserved. The ester group catalyzed by the esterification accelerator has reaction reversibility, can be hydrolyzed with water under proper conditions, and can release the shielded silicon hydroxyl again, so that the recovery of the silicon hydroxyl can be realized by washing, the quantity of the hydroxyl on the surface of the silica gel is greatly maintained, and the reduction of the silica gel caused by excessive dehydration condensation is avoided, so that the adsorption performance is reduced. In this way, part of the hydroxyl groups can be protected in advance during the polymerization of silicic acid, so that they no longer participate in the polymerization of silicic acid into silica gel. After the silica gel is shaped, releasing silicon hydroxyl groups, and keeping a certain amount of hydroxyl groups for adsorbing substances which are easy to generate turbidity; proper and insufficient polymerization of the orthosilicic acid is also beneficial to the protection of the silica gel pore canal structure.
It can be seen that the preparation method of the present invention can combine with hydroxyl groups to form esters when the hydroxyl groups are temporarily protected, and can remove the hydroxyl reversible shielding agent at any time to reduce the hydroxyl groups when the silicon hydroxyl groups are required. Can simultaneously realize the regulation and control of the silica gel pore canal structure and the maintenance of the surface silicon hydroxyl number, and avoid the quantity loss caused by excessive silicon hydroxyl participating in the excessive dehydration condensation reaction of the orthosilicic acid.
The preparation method improves the controllability of the size of the silica gel pore canal to a new level, and can simultaneously realize the protection of the number of silicon hydroxyl groups.
Drawings
FIG. 1 is a scanning electron microscope image of a small pore silica gel clarifier of the present invention.
Detailed Description
The following describes the technical scheme of the invention in detail.
Example 1
The preparation method of the small-pore silica gel clarifying agent comprises the following specific steps:
(1) Preparing sol:
firstly, adding a hydroxyl reversible shielding agent into a sodium silicate solution with the mass fraction of 20wt%, and uniformly mixing; then adding a sulfuric acid solution with the mass fraction of 30wt% into a sodium silicate solution, mixing and reacting at 20 ℃, and adjusting the pH value of a mixed system to 3; after stirring for 10min, reacting for 2h, keeping the pH value at 4, and preparing the sol.
The hydroxyl reversible shielding agent is prepared by compounding esterification reaction accelerator N-hydroxysuccinimide, carboxyl activating agent EDC and succinic acid; wherein, succinic acid: n-hydroxysuccinimide: the molar ratio of EDC is 1:1:1; the succinic acid: the molar ratio of sodium silicate is 5:1.
(2) Preparing gel: firstly, aging the sol obtained in the step (1) for 2 hours at 60 ℃; soaking in 30wt% NaOH solution for 15min, and washing with water at 25deg.C to obtain gel. Wherein the water washing liquid consists of ethanol and K 2CO3 aqueous solution with the pH value of 12 according to the volume ratio of 1:1.
(3) Preparing a small-pore silica gel clarifying agent: and (3) drying the gel prepared in the step (2) at 60 ℃ for 48 hours, and then placing the gel in a muffle furnace at 500 ℃ for high-temperature activation for 2 hours to obtain the small-pore silica gel clarifying agent.
When the obtained small-pore silica gel clarifying agent is used for the haze prevention treatment of beer, the following steps can be adopted: mixing the prepared small-pore silica gel clarifying agent with beer according to the mass ratio of 1:7 at 25 ℃, reacting for 2 hours, and filtering by using diatomite to remove the clarifying agent, thus finishing beer clarifying operation.
As can be seen in fig. 1, the resulting small pore silica gel clarifier is composed of nanoparticles, with each particle being composed of smaller agglomerates of nanoparticles.
Example 2
The preparation method of the small-pore silica gel clarifying agent comprises the following specific steps:
(1) Preparing sol:
firstly, adding a hydroxyl reversible shielding agent into a sodium silicate solution with the mass fraction of 20wt%, and uniformly mixing; then adding a sulfuric acid solution with the mass fraction of 30wt% into a sodium silicate solution, mixing and reacting at 40 ℃, and adjusting the pH value of a mixed system to be 2; after stirring for 10min, reacting for 2h, and keeping the pH value at 3 to prepare the sol.
The hydroxyl reversible shielding agent is prepared by compounding an esterification reaction accelerator N-hydroxysuccinimide, a carboxyl activating agent DCC and butyric acid; wherein, butyric acid: n-hydroxysuccinimide: the molar ratio of DCC is 0.5:1:0.5; the butyric acid: the molar ratio of sodium silicate is 10:1.
(2) Preparing gel: firstly, aging the sol obtained in the step (1) for 2 hours at 60 ℃; soaking in 30wt% NaOH solution for 15min, and washing with water at 20deg.C to obtain gel; wherein the water washing liquid consists of ethanol and Na 2CO3 aqueous solution with the pH value of 10 according to the volume ratio of 10:1.
(3) Preparing a small-pore silica gel clarifying agent: and (3) drying the gel prepared in the step (2) at 180 ℃ for 2 hours, and then placing the gel in a muffle furnace at 400 ℃ for high-temperature activation for 96 hours to obtain the small-pore silica gel clarifying agent.
When the obtained small-pore silica gel clarifying agent is used for the haze prevention treatment of beer, the following steps can be adopted: mixing the prepared small-pore silica gel clarifying agent with beer according to the mass ratio of 1:10 at the temperature of 5 ℃, reacting for 2.5 hours, and filtering by using diatomite to remove the clarifying agent, thus finishing the beer clarifying operation.
Example 3
The preparation method of the small-pore silica gel clarifying agent comprises the following specific steps:
(1) Preparing sol:
Firstly, adding a hydroxyl reversible shielding agent into a sodium silicate solution with the mass fraction of 20wt%, and uniformly mixing; then adding a sulfuric acid solution with the mass fraction of 30wt% into a sodium silicate solution, mixing and reacting at 30 ℃, and adjusting the pH value of a mixed system to 3; after stirring for 10min, reacting for 2h, keeping the pH value at 4, and preparing the sol.
The hydroxyl reversible shielding agent is prepared by compounding esterification reaction accelerator N-hydroxysuccinimide, carboxyl activating agent DIC and benzoic acid; wherein, benzoic acid: n-hydroxysuccinimide: the molar ratio of DIC is 2:1:2; the carboxylic acid: the molar ratio of sodium silicate is 0.5:1.
(2) Preparing gel: firstly, aging the sol obtained in the step (1) for 2 hours at 60 ℃; soaking in 30wt% NaOH solution for 15min, and washing with water at 25deg.C to obtain gel; wherein the water washing liquid consists of ethanol and K 2CO3 aqueous solution with the pH value of 13 according to the volume ratio of 0.5:1.
(3) Preparing a small-pore silica gel clarifying agent: and (3) drying the gel prepared in the step (2) at 100 ℃ for 24 hours, and then placing the gel in a muffle furnace at 450 ℃ for high-temperature activation for 48 hours to obtain the small-pore silica gel clarifying agent.
When the obtained small-pore silica gel clarifying agent is used for the haze prevention treatment of beer, the following steps can be adopted: mixing the prepared small-pore silica gel clarifying agent with beer according to the mass ratio of 1:5 at 15 ℃, reacting for 2 hours, and filtering by using diatomite to remove the clarifying agent, thus finishing beer clarifying operation.
Example 4
The difference from example 1 is that the hydroxyl reversible shielding agent in the step (1) is compounded by N-hydroxysuccinimide as an esterification reaction accelerator, EDCI as a carboxyl activating agent and fumaric acid.
Otherwise, the same as in example 1 was conducted.
Example 5
The difference from example 1 is that the hydroxyl reversible shielding agent in the step (1) is compounded by N-hydroxysuccinimide as an esterification reaction accelerator, EDC as a carboxyl activating agent and terephthalic acid.
Otherwise, the same as in example 1 was conducted.
Example 6
The difference from example 1 is that the hydroxyl reversible shielding agent in the step (1) is compounded by N-hydroxysuccinimide as an esterification reaction accelerator, EDC as a carboxyl activating agent and caproic acid.
Otherwise, the same as in example 1 was conducted.
Example 7
The difference from example 1 is that the hydroxyl reversible shielding agent in the step (1) is compounded by N-hydroxysuccinimide as an esterification reaction accelerator, EDC as a carboxyl activating agent and maleic acid.
Otherwise, the same as in example 1 was conducted.
Example 8
The difference from example 1 is that the hydroxyl reversible shielding agent in the step (1) is compounded by N-hydroxysuccinimide as an esterification reaction accelerator, EDC as a carboxyl activating agent and propionic acid.
Otherwise, the same as in example 1 was conducted.
Example 9
The difference with the embodiment 1 is that the hydroxyl reversible shielding agent in the step (1) is compounded by N-hydroxysuccinimide serving as an esterification reaction accelerator, EDC serving as a carboxyl activating agent and succinic acid; wherein, succinic acid: n-hydroxysuccinimide: the molar ratio of EDC was 1:1:0.5.
Otherwise, the same as in example 1 was conducted.
Example 10
The difference from example 1 is that the hydroxyl reversible screening agent in step (1) consists of succinic acid: n-hydroxysuccinimide: the molar ratio of EDC was 1:1:2.
Otherwise, the same as in example 1 was conducted.
Comparative example 1
The difference from example 1 is that the hydroxyl reversible shielding agent in the step (1) is compounded by N-hydroxysuccinimide as an esterification reaction accelerator, EDC as a carboxyl activating agent and formic acid.
Otherwise, the same as in example 1 was conducted.
Comparative example 2
The difference from example 1 is that the hydroxyl reversible shielding agent in the step (1) is compounded by N-hydroxysuccinimide as an esterification reaction accelerator, EDC as a carboxyl activating agent and acetic acid.
Otherwise, the same as in example 1 was conducted.
Comparative example 3
The difference from example 1 is that the hydroxyl reversible shielding agent in the step (1) is compounded by N-hydroxysuccinimide as an esterification reaction accelerator, EDC as a carboxyl activating agent and oxalic acid.
Otherwise, the same as in example 1 was conducted.
Comparative example 4
The difference from example 1 is that the hydroxyl reversible shielding agent in the step (1) is compounded by N-hydroxysuccinimide as an esterification reaction accelerator, EDC as a carboxyl activating agent and citric acid.
Otherwise, the same as in example 1 was conducted.
Comparative example 5
The difference from example 1 is that the hydroxyl reversible shielding agent in the step (1) is compounded by N-hydroxysuccinimide as an esterification reaction accelerator, EDC as a carboxyl activating agent and lactic acid.
Otherwise, the same as in example 1 was conducted.
Comparative example 6
The difference from example 1 is that the hydroxyl reversible shielding agent in the step (1) is compounded by N-hydroxysuccinimide as an esterification reaction accelerator, EDC as a carboxyl activating agent and acrylic acid.
Otherwise, the same as in example 1 was conducted.
The relevant indexes of the small-pore silica gel clarifying agent prepared in each example and comparative example are shown in Table 1 in detail.
Table 1 correlation index of each silica gel clarifier
Experimental example 1
1. The purpose of the experiment is as follows: the effect of carboxylic acid usage on various indicators of the silica gel clarifying agent was examined.
2. The experimental method comprises the following steps: referring to the preparation method step described in example 1, a single variable was set as succinic acid in step (1): the molar ratio of sodium silicate is 0.2:1, 0.5:1, 1:1, 3:1, 5:1, 7:1, 9:1, 10:1, 11:1, respectively. Other steps and conditions were the same as in example 1.
3. Experimental results: details are shown in Table 2.
TABLE 2 correlation index for silica gel clarifying agents
Experimental example 2
1. The purpose of the experiment is as follows: the influence of the reaction temperature on each index of the silica gel clarifying agent is examined.
2. The experimental method comprises the following steps: referring to the preparation method step described in example 1, a single variable was set such that the temperature of mixing and reaction in step (1) was 15 ℃, 20 ℃, 25 ℃, 30 ℃, 35 ℃, 40 ℃ and 45 ℃ respectively. Other steps and conditions were the same as in example 1.
3. Experimental results: details are shown in Table 3.
TABLE 3 correlation index for each silica gel clarifier
Therefore, the accurate control of the addition amount of carboxylic acid, the esterification reaction accelerator and the carboxyl activating agent and the reaction temperature has an important influence on realizing the accurate adjustment of the pore diameter of the silica gel clarifying agent in a certain range.

Claims (10)

1. The preparation method of the small-pore silica gel clarifying agent is characterized by comprising the following steps of:
(1) Preparing sol:
firstly, adding a hydroxyl reversible shielding agent into a raw material sodium silicate solution, and uniformly mixing;
Then adding the raw material sulfuric acid solution into the sodium silicate solution, mixing and reacting at 20-40 ℃, and regulating the pH value of the mixed system to 2-4;
after the reaction is finished, maintaining the pH value at 3-4 to prepare sol;
the hydroxyl reversible shielding agent is compounded by an esterification reaction accelerator, a carboxyl activating agent and carboxylic acid; wherein, carboxylic acid: esterification reaction accelerator: the molar ratio of the carboxylic acid group activator is 0.1-5:1:0.5-2;
the carboxylic acid: the molar ratio of the sodium silicate is 0.5-10:1;
The carboxylic acid is one or more of propionic acid, butyric acid, valeric acid, caproic acid, benzoic acid, phenylacetic acid, succinic acid, adipic acid, phthalic acid, isophthalic acid, terephthalic acid, fumaric acid or maleic acid;
The carboxyl activating agent is one or more of 1-ethyl- (3-dimethylaminopropyl) carbodiimide hydrochloride, dicyclohexylcarbodiimide, diisopropylcarbodiimide or 1- (3-dimethylaminopropyl) -3-ethylcarbodiimide;
the esterification reaction promoter is N-hydroxysuccinimide;
(2) Preparing gel: aging the sol obtained in the step (1) and soaking with alkali, and then washing with a water washing solution to obtain gel;
Wherein the water washing liquid consists of ethanol and alkaline aqueous solution with the pH value of 9-14;
(3) Preparing a small-pore silica gel clarifying agent: and (3) drying and activating the gel prepared in the step (2) to obtain the small-pore silica gel clarifying agent.
2. The method for preparing a silica gel clarifier with small pore diameter according to claim 1, wherein carboxylic acid in the hydroxyl reversible shielding agent of the step (1): esterification reaction accelerator: the molar ratio of the carboxylic acid group activator is 1:1:1.
3. The method for preparing a silica gel clarifier with small pore diameter according to claim 1, wherein the carboxylic acid in the hydroxyl reversible shielding agent in the step (1) is one or more of butyric acid, caproic acid, benzoic acid, succinic acid, terephthalic acid or fumaric acid.
4. The method for preparing a silica gel clarifier with small pore size according to claim 1, wherein the alkaline aqueous solution in the step (2) is K 2CO3 aqueous solution or Na 2CO3 aqueous solution.
5. The method for preparing a small pore silica gel clarifier according to claim 1, wherein the water washing liquid of the step (2) comprises ethanol: the volume ratio of the alkaline aqueous solution is 0.1-10:1.
6. The method for preparing a silica gel clarifier of small pore size according to claim 1, wherein the water washing temperature in the step (2) is 20-25 ℃.
7. The method for preparing a silica gel clarifier with small pore size according to claim 1, wherein the drying temperature in the step (3) is 60-180 ℃ and the drying time is 2-48h.
8. The method for preparing a silica gel clarifier with small pore diameter according to claim 1, wherein the activation in the step (3) adopts a roasting method, the roasting temperature is 400-500 ℃, and the roasting time is 2-96h.
9. A small pore silica gel clarifier characterized in that it is prepared by the preparation method of any one of claims 1-8; the pore diameter of the silica gel clarifying agent is 4-8nm, the specific surface area is 550-800m 2/g, and the retention rate of silicon hydroxyl is 65-90%.
10. Use of a small pore silica gel clarifier according to claim 9 for purification treatment of medical waste water or anti-haze treatment of beer.
CN202410430786.4A 2024-04-11 2024-04-11 Small-pore silica gel clarifying agent and preparation method and application thereof Active CN118022701B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202410430786.4A CN118022701B (en) 2024-04-11 2024-04-11 Small-pore silica gel clarifying agent and preparation method and application thereof

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202410430786.4A CN118022701B (en) 2024-04-11 2024-04-11 Small-pore silica gel clarifying agent and preparation method and application thereof

Publications (2)

Publication Number Publication Date
CN118022701A true CN118022701A (en) 2024-05-14
CN118022701B CN118022701B (en) 2024-07-05

Family

ID=90989725

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202410430786.4A Active CN118022701B (en) 2024-04-11 2024-04-11 Small-pore silica gel clarifying agent and preparation method and application thereof

Country Status (1)

Country Link
CN (1) CN118022701B (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN118289988A (en) * 2024-06-05 2024-07-05 齐鲁工业大学(山东省科学院) Method for treating traditional Chinese medicine pharmaceutical wastewater

Citations (18)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1379917A (en) * 1971-12-03 1975-01-08 Monsanto Ltd Clarification of beer
US5229096A (en) * 1990-11-19 1993-07-20 Scm Chemicals, Inc. Silica gel
JP2004250387A (en) * 2003-02-20 2004-09-09 Wako Pure Chem Ind Ltd Method for catalytic hydrogenation reaction using palladium carried by silica gel with dual pore system
JP2007033436A (en) * 2005-06-24 2007-02-08 Sumika Chemical Analysis Service Ltd Silica gel carrier and optical resolution method using it
CN101456569A (en) * 2008-07-22 2009-06-17 绍兴纳诺气凝胶新材料研发中心有限公司 Method for quick-speed preparing aerogel by hydro-thermal synthesis at low cost
CN101569850A (en) * 2009-03-07 2009-11-04 垦利三合新材料科技有限责任公司 Preparation method of high-adsorption-value adjustable-pore-volume micro-powder silica gel
CN103159251A (en) * 2011-12-15 2013-06-19 贵州省纳米材料工程中心 Preparation method for modified transparent nano-zinc oxide sol
CN104445222A (en) * 2014-11-27 2015-03-25 齐鲁工业大学 Preparation method of acidic silica sol with large particle size and uniform distribution
CN105565329A (en) * 2016-03-17 2016-05-11 仇颖莹 Preparation method of macroporous charged beer silica gel particles
CN109044963A (en) * 2018-09-30 2018-12-21 齐鲁工业大学 A kind of injection pH sensitivity nano-hydrogel and preparation method thereof
CN111229156A (en) * 2020-01-20 2020-06-05 齐鲁工业大学 Preparation and application of hydroxyapatite modified mesoporous silica adsorption material
CN113181370A (en) * 2021-05-18 2021-07-30 六安市康恒生物科技有限公司 Synthesis process of tumor targeting drug
CN114931927A (en) * 2022-05-04 2022-08-23 中海油天津化工研究设计院有限公司 Adsorbent for adsorbing and separating aromatic hydrocarbons in gasoline and diesel oil and preparation method thereof
CN115215346A (en) * 2022-08-15 2022-10-21 山东邦凯新材料有限公司 Pore diameter controllable silicon dioxide and preparation method and application thereof
CN115608341A (en) * 2022-10-24 2023-01-17 南通大江化学有限公司 Preparation method of high-performance silica gel composite drying agent
CN115676841A (en) * 2022-10-27 2023-02-03 金三江(肇庆)硅材料股份有限公司 Beer silica gel and preparation method thereof
CN116328743A (en) * 2023-05-11 2023-06-27 北京工业大学 Preparation method of composite material for in-situ growth of microcrystals on clinoptilolite surface
CN117244533A (en) * 2023-10-10 2023-12-19 南京工业大学 Adsorbent for recycling and pretreatment of acetonitrile waste liquid and preparation method and application thereof

Patent Citations (18)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1379917A (en) * 1971-12-03 1975-01-08 Monsanto Ltd Clarification of beer
US5229096A (en) * 1990-11-19 1993-07-20 Scm Chemicals, Inc. Silica gel
JP2004250387A (en) * 2003-02-20 2004-09-09 Wako Pure Chem Ind Ltd Method for catalytic hydrogenation reaction using palladium carried by silica gel with dual pore system
JP2007033436A (en) * 2005-06-24 2007-02-08 Sumika Chemical Analysis Service Ltd Silica gel carrier and optical resolution method using it
CN101456569A (en) * 2008-07-22 2009-06-17 绍兴纳诺气凝胶新材料研发中心有限公司 Method for quick-speed preparing aerogel by hydro-thermal synthesis at low cost
CN101569850A (en) * 2009-03-07 2009-11-04 垦利三合新材料科技有限责任公司 Preparation method of high-adsorption-value adjustable-pore-volume micro-powder silica gel
CN103159251A (en) * 2011-12-15 2013-06-19 贵州省纳米材料工程中心 Preparation method for modified transparent nano-zinc oxide sol
CN104445222A (en) * 2014-11-27 2015-03-25 齐鲁工业大学 Preparation method of acidic silica sol with large particle size and uniform distribution
CN105565329A (en) * 2016-03-17 2016-05-11 仇颖莹 Preparation method of macroporous charged beer silica gel particles
CN109044963A (en) * 2018-09-30 2018-12-21 齐鲁工业大学 A kind of injection pH sensitivity nano-hydrogel and preparation method thereof
CN111229156A (en) * 2020-01-20 2020-06-05 齐鲁工业大学 Preparation and application of hydroxyapatite modified mesoporous silica adsorption material
CN113181370A (en) * 2021-05-18 2021-07-30 六安市康恒生物科技有限公司 Synthesis process of tumor targeting drug
CN114931927A (en) * 2022-05-04 2022-08-23 中海油天津化工研究设计院有限公司 Adsorbent for adsorbing and separating aromatic hydrocarbons in gasoline and diesel oil and preparation method thereof
CN115215346A (en) * 2022-08-15 2022-10-21 山东邦凯新材料有限公司 Pore diameter controllable silicon dioxide and preparation method and application thereof
CN115608341A (en) * 2022-10-24 2023-01-17 南通大江化学有限公司 Preparation method of high-performance silica gel composite drying agent
CN115676841A (en) * 2022-10-27 2023-02-03 金三江(肇庆)硅材料股份有限公司 Beer silica gel and preparation method thereof
CN116328743A (en) * 2023-05-11 2023-06-27 北京工业大学 Preparation method of composite material for in-situ growth of microcrystals on clinoptilolite surface
CN117244533A (en) * 2023-10-10 2023-12-19 南京工业大学 Adsorbent for recycling and pretreatment of acetonitrile waste liquid and preparation method and application thereof

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN118289988A (en) * 2024-06-05 2024-07-05 齐鲁工业大学(山东省科学院) Method for treating traditional Chinese medicine pharmaceutical wastewater

Also Published As

Publication number Publication date
CN118022701B (en) 2024-07-05

Similar Documents

Publication Publication Date Title
CN118022701B (en) Small-pore silica gel clarifying agent and preparation method and application thereof
CA3082668C (en) Plant fiber-based intelligent adsorptive material with multi-adsorption sites and preparation method and use thereof
CN109231387B (en) Straw/polyaluminium chloride composite water treatment material and preparation method thereof
CN112875831B (en) Water quality improver for aquaculture, preparation method thereof and application thereof in water purification
US20050170402A1 (en) Method of separating substance from liquid
CN113368833B (en) Inorganic-organic flocculant and preparation method thereof
CN114225916B (en) Method for adsorbing antibiotics in sewage by using sulfonated alkali lignin-based polyvinyl formal sponge
CN115893540A (en) Water purifying agent for chemical organic wastewater treatment and preparation method thereof
CN112642405B (en) Recyclable adsorbent and preparation method and application thereof
KR100533873B1 (en) Producing method of biosorbent for heavy metal removal and biosorbent produced therefrom
CN118416863A (en) Protein adsorbent for separating and purifying hyaluronic acid and preparation method and application method thereof
CN113908697A (en) High-performance ceramic membrane component applied to beer filtration field
CN114380373A (en) Composite coagulant, preparation method thereof and application thereof in treatment of secondary effluent of sewage plant
CN113198424A (en) Preparation method of lanthanum hydroxide-loaded non-woven fabric filter adsorption dephosphorization material
CN115140799B (en) Printing and dyeing wastewater treatment agent and preparation method thereof
CN112341938A (en) Ceramic tile polishing solution containing composite antibacterial photocatalytic material and preparation process thereof
CN111995016A (en) Coagulant for removing humic acid and preparation method and application thereof
CN117509997B (en) Pretreatment method of steelmaking wastewater
CN115504597B (en) Thallium removal process for pyrite contaminated acid
CN110921753B (en) Ternary graft copolymerization modified spirulina protein water quality clarifying agent and preparation method thereof
CN112808248B (en) Adsorption material applied to mercury removal of wastewater and preparation method and application thereof
KR20180077859A (en) Adsorbent with excellent formability and preparation method thereof
CN112569806B (en) Polyvinylidene fluoride mixed matrix membrane with white spirit catalytic filtration performance and preparation and application thereof
CN115367956A (en) Method for adsorbing macromolecular organic matters by using modified hectorite
CN113912148A (en) Polyacrylamide water purifying agent and preparation method thereof

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant